Headlight for cars



April 195-6 ISAO YAMASHITA HEADLIGHT FOR CARS Filed April 16, 1963 INVENTOR.

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rrr n ATTORNEYS United States Patent 3,247,416 HEADLIGHT FOR CARS Isao Yamashita, Yokosuka, Japan (833 l-chome Higashimachi, Kogamei, Tokyo, Japan) Filed Apr. 16, 1963, Ser. No. 273,338 4 Claims. (Cl. 313110) This invention relates to headlights for motor vehicles, and more particularly to an improved headlight lamp of the sealed beam type.

A main object of the invention is to provide a novel and improved sealed beam headlamp which is relatively simple in construction, which produces minimum glare, particularly with respect to the upper portion of the beam therefrom, which provides efiicient production of light in relation to its Wattage, and Which may be installed in a standard headlight casing without requiring any modification of the casing.

A further object of the invention is to provide an improved sealed beam headlight which is inexpensive to manufacture, which is sturdy in construction, which is provided with an externally exposed cooling surface adjacent its primary reflector, said cooling surface being directly exposed to and cooled by the atmosphere, which is relatively compact in size, and which is mechanically interchangeable with standard sealed beam headlight bulbs.

A still further object of the invention is to provide an improved sealed beam headlight which provides a high light output without glare, the upper portion of the front lens thereof being shielded against direct transmission of light rays therethrough from the lamp filament, which is easy to install, and which is easy to connect to a motor vehicle energizing circuit.

Further objectsand advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

FIGURE 1 is a rear perspective view of an improved sealed beam headlight bulb constructed in accordance with the present invention.

FIGURE 2 is a front elevational view of the sealed beam headlight bulb of FIGURE 1.

FIGURE 3 is an enlarged transverse vertical cross sectional view taken substantially on the line 33 of FIGURE 2.

FIGURE 4 is an enlarged horizontal cross sectional view taken substantially on the line 44 of FIGURE 2.

Referring to the drawings, 11 generally designates an improved sealed beam headlight unit constructed in accordance With the present invention. The unit 11 comprises a sealed evacuated housing, designated generally at 12 and comprising a generally circular transparent front wall 13, which may be externally convex, for example, which may be spherical in shape, as shown in FIGURES 3 and 4. The housing 12 is provided with the outwardly projecting peripheral rim or flange 14 which is adapted to be received in the retaining ring of a standard sealed beam headlight assembly, the retaining ring holding the flange 14 in a manner to retain the sealed beam headlight in proper position on a motor vehicle. The flange 14 is identical to the peripheral flange found on a conventional or standard sealed beam headlamp.

Designated at 15 is a substantially flat vertical upper rear wall segment which extends downwardly from the periphery of the housing 12 and which terminates substantially at a transverse horizontal diameter of the housing, namely, at the diametral bottom edge 16 shown in FIG- URE 3. Designated at 17 is a lower rear wall segment which extends upwardly from the periphery of the housing 12 and which is generally spherical in shape, being rearwar ly convex and terminating at its upper edge in the horizontal plane which contains the bottom edge of the upper rear wall segment 15. Thus, the arcuately curved top edge of the lower rear wall segment 17 is rearwardly offset from the straight bottom edge 16 of the upper rear wall segment 15 and is connected thereto by the horizontal intermediate rear wall segment 18. v Formed integrally in the intermediate portion of the horizontal rear wall segment 18 and projecting upwardly therefrom is the substantially hemispherical auxiliary housing 19 which faces downwardly, namely, towards the inside surface of the curved lower rear wall segment 17.

The lower rear wall segment 17 may be of any desired curvature, for example, may be of spherical curvature, as above mentioned, or alternatively, may be parabolic, elliptical, or of any other desired curvature, in accordance with the desired distribution of light rays reflected therefrom.

The auxiliary housing 19 thus defines a downwardly concave cavity, and the inside surface of said cavity is provided with a coating 20 of suitable reflective material, said coating being of suflicient thickness so that it prevents the transmission of light rays directly therethrough. The inside surface of the lower rear wall segment 17 is similarly provided with a reflective coating 21.

Sealingly secured in the horizontal intermediate rear wall segment 18 are a pair of terminal studs 22, 22 located symmetrically at opposite sides of the integral hemispherical auxiliary housing 19. As shown in FIGURE 4, the terminal studs 22, 22 are preferably located on a line containing a diameter of the auxiliary housing 19 which is substantially parallel to the plane of the peripheral rim 14. Secured to the bottom ends of the studs 22, 22 and extending along said diameter is the lamp filament 24, which is thus substantially centered in the auxiliary housing 19 and supported in a position such that direct light rays therefrom cannot pass above the bottom edge 16 of the upper rear wall segment 15, whereby said light rays are constrained to pass beneath the bottom edge 16, and whereby direct light rays from the filament 24 can only pass through the lower half of the transparent front lens 13.

The terminal studs 22, 22 are connected by suitable wires 25, 25 to the energizing circuit of the associated motorvehicle, clamping nuts 26 being provided on the terminal studs for fastening the ends of the wires 25 thereto. As will be readily apparent from FIGURE 1, the clamping nuts 26, 26 are easily accessible, since they are exposed above the horizontal rear wall segment 18 and are located adjacent opposite sides of the auxiliary housing 18, ample space being provided 'for manipulating the clamping nuts.

As above mentioned, the direct light rays from the filament 24 are constrained to pass only through the lower half of the transparent front lens 13. Also passing through the lower half of the transparent front lens are reflected rays, namely rays which are reflected from the primary reflecting layer 20 on the inside surface of the auxiliary housing 19. Additional light rays from the filament 24 are reflected forwardly through the transparent front lens 13 by the reflecting layer 21 on the curved lower rear wall segment 17, the reflective surface 21 receiving rays not only directly from the filament 24 but also from the primary reflector 20. The rays from the bottom reflector 21 pass through the upper portion of the front lens 13 as well as through the lower portion thereof. However, the major portion of the light rays originating at the filament 24 pass through the lower portion of the transparent front lens 13, namely, are confined to the portion of the lens located below the horizontal plane containing the bottom edge 16 of upper rear wall segment 15. As a result, the major portion of the light generated by the filament 24 is directed downwardly so as to illuminate the roadway in front of the associated vehicle,

whereas the light intensity in a direction upwardly and forwardly of the headlamp assembly is relatively low.

It will be noted that the top surface of the auxiliary housing 19, as well as the adjacent portions of the horizontal rear wall segment 18 are freely exposed to the atmosphere and thus are directly cooled by atmospheric air.

While the upper rear wall segment 15 is illustrated as being substantially flat, it may have any desired curva- 'ture, which is however relatively small as compared to the amount of curvature of the lower rear wall segment 17, whereby to provide an intermediate horizontal connecting wall segment 18 of substantial area.

While a specific embodiment of an improved sealed beam headlight unit has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. A sealed beam headlight unit comprising a housing having a transparent front wall, an upper rear wall segment extending downwardly from the periphery of the housing to a horizontal intermeidate plane of the housing, a lower rear wall segment extending upwardly from the periphery of the housing substantially to said plane and having its top edge off-set rearwardly from the bottom edge of the upper rear wall segment, an intermediate horizontal rear wall segment connecting the top edge of the lower rear wall segment to the bottom edge of the upper rear wall segment, means on the intermediate rear wall segment defining a downwardly concave cavity, and a filament mounted in said downwardly concave cavity, said cavity and the bot-tom rear wall segment having reflective inner surfaces and being shaped to direct light rays from said filament through said transparent front wall.

2. A sealed beam headlight unit comprising a generally circular housing having a transparent front wall, a substantially fiat vertical upper rear wall segment extending from the periphery of the housing to the horizontal diameter thereof, an externally convex lower rear wall segment, a flat horizontal intermediate rear wall segment connecting the top edge of said lower rear wall segment to the bottom edge of said upper rear Wall segment, a downwardly concave cavity formed in said horizontal wall segment, and a filament mounted horizontally in said cavity, the cavity and the lower rear wall segment having substantially reflective inner surfaces and being shaped so as to direct light rays from said filament through said front wall, the Wall of the cavity being substantially impervious to transmission of light rays therethrough.

3. A sealed beam headlight unit comprising a generally circular housing having a transparent front wall, a substantially fiat vertical upper rear wall segment extending from the periphery of the housing to the horizontal diameter thereof, an externally convex lower rear wall segment, a flat horizontal intermediate rear wall segment connecting the top edge of said lower rear wall segment to the bottom edge of said upper rear wall segment, a downwardly concave cavity formed in said horizontal rear wall segment, respective terminals on said horizontal rear Wall segment on opposite sides of said cavity, and a filament mounted horizontally in said cavity and connected between said terminals, the cavity and the lower rear wall segment having substantially reflective inner surfaces and being shaped so as to direct light rays from said filament through said front wall, the wall of the cavity being substantially impervious to transmission of light rays therethrough.

4. A sealed beam headlight unit comprising a generally circular housing having a transparent front wall, a substantially fiat vertical upper rear wall segment extending downwardly from the periphery of the housing to the horizontal diameter thereof, an externally convex lower rear wall segment, a flat horizontal intermediate rear wall segment connecting the top edge of said lower rear wall segment to the bottom edge of said upper rear wall segment, a downwardly concave substantially hemispherical upstanding auxiliary housing formed integrally on said horizontal rear wall segment, respective terminals on said horizontal rear wall segment on opposite sides of said auxiliary housing, and a filament mounted horizontally in said auxiliary housing and connected between said terminals, the auxiliary housing and the lower rear wall segment having substantially reflective inner surfaces and being shaped so as to direct light rays from said filament through said front wall, the wall of the auxiliary housing being substantially impervious to direct transmission of light rays therethrough.

No references cited.

JOHN W. HUCKERT, Primary Examiner.

A. J. JAMES, Assistant Examiner. 

1. A SEALED BEAM HEADLIGHT UNIT COMPRISING A HOUSING HAVING A TRANSPARENT FRONT WALL, AN UPPER REAR WALL SEGMENT EXTENDING DOWNWARDLY FROM THE PERIPHERY OF THE HOUSING TO A HORIZONTAL INTERMEDIATE PLANE OF THE HOUSING, A LOWER REAR WALL SEGMENT EXTENDING UPWARDLY FROM THE PERIPHERY OF THE HOUSING SUBSTANTIALLY TO SAID PLANE AND HAVING ITS TOP EDGE OFFSET REARWARDLY FROM THE BOTTOM EDGE OF THE UPPER REAR WALL SEGMENT, AN INTERMEDIATE HORIZONTAL REAR WALL SEGMENT CONNECTING THE TOP EDGE OF THE LOWER REAR WALL SEGMENT TO THE BOTTOM EDGE 